Pump



Nov. 7,1944. I D, N EVANSy www PUMP Fild Feb. 4, 1945 3 Sheets-Sheet l Nov. 7, 1944.

D. N. EVANS PUMP Filed Feb. 4, 1943 3 Sheets-Sheet 2 @ww/f Nov. 7, 1944.

D. N. EVANS 2,362,365

PUMP

Filed Feb. 4, 1943 3 Sheets-Sheet 3 P07779 ope?? Maefon Patented Nov. 7,

'UNITED-Q STAT 151sl PTEN T f OFFICE PUMP' Douglas N.' Evans, Gary, Ind., assignor yto Inland Steel Company, Chicago, Ill., a corporation of/ 'Dslam application r'esru'ny 4, 1943, ser'1a1 4 claims. (ci. 10s-z) My invention relates to pumps for pumping, by way of example and more particularly, though not exclusively, non-gaseous .fluids such as those used as hydraulic mediums and grease or oil to be supplied under pressure for lubricating purposes and moreespecially to pumps of .the type em' playing a main pumping piston and auxiliary piston valve means operating in timed relation to the pumping piston and controlling the fluid flow.

My object generally stated is to provide a construction of 'pump of the type above referred to which will be highly improved over pumps of this type as hitherto constructed, and, as to its use in certain situations, simplify construction oi' the structure and dispense with ladiuncts thereto such as, for example, reversing valve mechanisms pensive to maintain in working condition. and at times'fail in operation.

'-Certain` follows:

To provide a pump for centralized. lubrication systems or `single-line double-flow centralized lubrication systems.

To provide a pump which will operate hydrau lic systems without hydraulic controls-where the operation of the pump is'electricaily contro1led.`

the pump being controlled solely by. the electric 'controls Examples of such systems are those provided -for operating cylinders o'n industrial equipi offmy more particular objects are as operating double-line provided in a flanged cylindrical block I4 housed in-an open-end of the casing Il l and -held in'place in any suitable way. The outer ends I5 and l5, o f the cylinders I I and I3Y are open -for flow of the iluid therethrough,` the outer end of the cylinder I2 being closed-by a plug `ll screwedu into this -which often give trouble in operation, are exment such as .presses'guide rolls, lifts. etc.; rais- -ing and lowering landing gear, wing flaps, etc.,

of aircraft; steering mechanism for marine vessels; and the control of parts-of machine tools.

To provide a pump which requires no packing and by which wear is' compensated for by mere adjustment oi parts oi' the pump.

To provide a pump by which reversal o'ifiow of I the' nuid operated on by the pump may be eiiected by merely reversing the direction4 of rotation 'of the shaft bymeans o f which the pump is driven, and

To provide aconstruction of. pump which may be stopped in any position without any of its ports becoming cross-connected thus locking the pump against iiow of the iluid therein when at rest.

Referring to the accompanying drawings:

Figure 1 is a plan sectional view o! bodying -my invention:

Figure 2 is a longitudinal sectional view oi the a pump em-v i The casing l0 r is shown'as cylinder.

The cylinder I2 connects with the cylinders Il and I3 by means of cross ports I3 and I9 located beyond the inner end of the plug Il and shown v as diametrically opposed. e 'Reciprocal in the cylinder I2 is a pumping piston andireciprocal in the cylinders II and I3 are valve pistons 2 l and 22, respectively. The pumping piston 20 and-valve pistons 2| and 22 are Apiviotaliy connected at yokes thereon, in@

dicated at 23, 24- and 25, with the straps 26, 2 1

and 28 of eccentrica 29, 30 and`3| secured to a drive-shaft 32 journalled in opposing sidewalls A of the casing I0, the eccentrics being disposedQ in diilerent angular positions about the shaft 32, in the particular construction shown, at angles "of 120 to each other.

having a funnel shaped opening 33 which communicates with a passage 3l, forming a port in the block I4 opening into the cylinder I2, the opening 33 communicating at its upper end with the lower -end of a reservoir 3l shown as of hopper form,'secured to the casing and provided to receive a supply o`f the-duid to be pumped.

i'he pump as provided is adapted for the pumping of fluid supplied to the pump through the outer end of either of the cylinders II or I3, selectively, or from the reservoir 35 in connection, with the supplying of the uid to the pump through either of these cylinders, for the discharge thereof through the other of these cylin- 'ders-merely by reversal of the direction of rotation of the drive shaft 32, or from tHe reservoir 35 only, through the cylinders II' and I3, selectively. merely by reversal of the direction of rotation of the drivelshaft 32 and the closing, in

pump, the section being taken at the broken line 2-2- on Figure 1 and viewed inthe direction of the arrow:

rime 'aaa-diagram uiustratins the piston I- displacement: and

any suitabieway, of the outer'end of the one of these two cylinders other than the one through which thedischarge is to be eected.

Assuming that the reservoir 35 is employed in a closed circuit system for making up any de f iciency i' fluid supplied to the pump through is a diagram showingthe timing of the' either of the cylinders II and I3; that the uid `to be 1pumped is in communication vwith the outer end I5 of the cylinder II, in which case the outer end I6 of the cylinder I3 would form the outlet for 'the pumped uid; and that'the shaft 32 is driven clockwise in Fig. 2; the valve piston 2 I, during the forepart of the back stroke of the pumping piston 20, moves to open the cylinder II to port I8 and consequently to the cylinder I2 whereupon fluid to be pumped enters the cylinder I2 'ahead of the pumping piston. As the pumping piston continues its rearward movement, the valve piston 2I.closes the cylpumping piston 20 the piston 20 closes the port 34 and thereupon the valve piston 22 moves backwardly to open the cylinder I2 to the port I9 and consequently tothe cylinder I3, the, valve piston 2| in these operations being closed, and

thus the charge of fluid in the cylinder I2 aheadv of the pumping piston 2|) is discharged through the port I3 into and Aout of the cylinder I3 to the yplace of use, by the action of the pumping pistn 20 augmented by the action of the valve piston 22.

As will be understood, a full .charge is prey sented to the pumping piston 20 for pumping regardless of any deficiency of. supply through the inlet cylinder II of the pump. `Where no such deficiency exists, such of the fluid as enters the cylinder I2 through port 34 on the rearward stroke of the piston 20 is returned to the reservoir 35 through port 34 on the forward stroke of the piston 20.

- Upon reversing the direction of rotation of the drive-shaft 32, the cylinder I3 becomes the vinlet of the pump, and the cylinder II, the outlet of the'pump, the valve piston 22 during the forepart of the back stroke of the pumping piston 20 moving to open the cylinder I3 to theport I9 and consequently to the cylinder I2 whereupon fluid to be pumped enters the cylinder I2 ahead of the pumping piston. As the pumping vpiston continues its rearward movement, the valvepiston 22 closes the cylinder I3 to the port I3 and the pumping piston 20 opens the reservoir 35 to the cylinder I2 through the port 34 and fluid to augment the charge ahead of the pumping piston flows frori the reservoir 35 into the cylinder I2, the valve piston 2I be- -ing closed in these operations and thus the cylinder II is out of communication with the supply fluid passages of the pum-p. A

On the forward or.|purnping stroke of the 'pumping piston 20, the"'piston 20 closes-the port 34 'and thereupon the valve piston 2i moves backwardly to open the cylinder I2 to the port I8 and consequently to the cylinder II, the valve piston 22 in these operations being closed -and thus the charge of fluid in the cylinder I2 ahead of the pumping piston 20 is discharged through theport I8 into and out of the cylinder I'I to the place of use by the action of the pumping pistonZ augmented by the action of the valve piston"'2I.

To ensure maximum efiiciency of the pump it' is necessary that the outlet of the pump at no tons 20, 2I and 22 as shownwhereby upon initiating pumping action of the pumping piston 20, following the closing of the pump. cylinder I2 to the fluid supply, in the rotation of the driveshaft 32 in either direction, the one of the valve pistons which controls the outlet of the pump remains closed for an instant, the compressivel pressure resulting xtherefrom becoming dissipated, as for example through the elasticity of the structure subjected to such pressure and/or the compressibility of the fluid or.` medium being pumped.

Furthermore .in those cases in which the reservoir 35 is used it is necessary that the port 34 at no time be in registration with the cylinder I2 when the port I9 or port I8 (when serving as an outletl'is in registration withthis cylinder, this being accomplished by locating the cut-off edge 34a of the port 34 as shown, whereby the piston 20 on ^its forward stroke closes this port before the piston 22 opens the port I9 for Adischarge through the cylinder I3 in the rotation required.

of the shaft 32 in one direction, or the piston 2| opens the port I3 for discharge through the cylinder II in the rotation of the shaft 32 in the opposite direction.

This is illustrated, by way of example, by the diagrams of Figures 3 and 4 wherein the relation between the port openings and the degrees of rotation of the shaft 32 (clockwise in Figure 2) in the above example, is shown.

In Figure 3 the relationship between the displacement of the several pistons and the degrees through which the drive shaft 32 is rotated in making one complete rotation is illustrated.

In further explanation of the diagrams of Figures 3 and 4 the cross-hatched areas represent the relation of the several port openings as indicated, to each other and to the degrees of rotation of the shaft 32 throughout one complete rotation (clockwise-in Figure 2) namely throughout 360, during which rotation no more than one of the three ports I8, I 9 and 34 is open at any one time, the spiral lines 20a, 2Ia and 22a in Figure 3 representing full reciprocations (throughout 360 of rotation of the shaft 32) of the several pistons 20, 2| and 22 respectively.

As shown, each port is open throughout less than of rotation of the shaft 32, by way of example and as shown, 119 only, and as the eccentrics 29, 30 and 3I are positioned about the shaft 32 at 120 to each other and as the several ports are opened in succession, each port is delayed in opening, after the preceding port has closed, throughout the rotation of vthe shaft 1*.1'r

When the pump is to be used without thereservoir, for selective pumping through either of the cylinders II and I3, it is necessary/(only to eliminate the reservoir or permanently/,close it to the cylinder I2, no change in the'pump being When all the uid to be pumped is supplied from the reservoir, it is only necessary that the one of the cylinders II and I3 through which the fluid is not to be pumped be closed permanently by any suitable means, no change in the pump time during the' back stroke of the pumping pis- `N5l being required.

As none of the ports of the pump, used for pumping in any of the diierentways above referred to, communicate with each other in any position to which the shaft v32 is rotated, ow of pump thus becoming locked against undesirable ow.

In the continued operation of the pump the cylinder and controlling said last-referred-to port, pistons in said valve cylinders cooperating iiuid in the pump regardless of the position in which the pump is stopped, cannot occur, the

original sharp-cornered edges of the outer ends of the pistons 2l and 22 are apt to wear, requir ing that the pistons 2l and 22 and ports I8 and I9 be relatively adjusted. This is provided for in the pump as shown by providing these ports in the block It which is lineally adjustable in the casing I0, the desired position o'f adjustment being maintained by interposing shim means 36 between the flange Ia of the block I5 and the adjacent end face of the casing lil.

While I have illustrated and described a particular construction of pump embodying my inwith said rst-referred-to ports to control communication between said pumpingl cylinder and said valve cylinders, and reversible means for reciprocating said pistons in said cylinders, cornprising a rotary reversible element having eccentric devices disposed about said element approximately 120 apart and operatively engaging said pistons for reciprocating them, said ports being so-positioned relative to the limits of the strokes of said pistons in their reciprocations that at no vention, I do not wish to be understood as intending to limit my invention thereto, as the same may beI variously modied and altered withoutw departing rom'the spirit of my invention.

What I claim as new, and desire to secure by Letters Patent, is: l

1. A pump having a pumping cylinder andl a plurality of valve cylinders, ports connecting said valve cylinders with said pumping cylinder and serving alternatively as inlet and outlet openings from said valve cylinders, an alternative outlet or inlet opening for each4 of said valve cylinders, a supply of uid to be pumped, al port through which said supply communicates with said pump? ing cylinder, a pumping piston in said pumping cylinder and controlling` said last-referred-to.

port, pistons insaid valve cylinders cooperating4 with said first-referred-to ports to' control com port, pistons in said vaive cylinders cooperating time'will vsaid valve cylindersv be vin communication with each other or with said second-named port in the operation of said means in either direction. d

3. A pump having a pumpingcylinder and a plurality of valve cylinders, ports connecting said valve cylinders with said pumping cylinder andserving alternatively as-'inlet and outlet openings from said valve cylinders, an alternative outlet or inlet opening for each of said valve cylinders, a supply of fluid to be pumped, a port through which said supply communicateswith said pumping cylinder, a pumping piston in said pumping cylinder and controlling said last-referred-to y with saidv rst-referred-to. ports to control 'com-- munication between saidpumping cylinder and said valve cylinders, and reversible means for reciprocating said pistons in said cylinders, said ports being so positioned relative to the limits of the strokes of said pistons in their reciprocations that at no time will said valve cylinders be in communication with each other or with said second-named port in the operation vof said means in either direction.

2. A pump having a pumping cylinder and `a plurality of valve cylinders, ports connecting said valve cylinders with said pumping cylinder and serving alternatively as inlet and outlet openings from said valve cylinders, an alternative outlet or inlet opening for each of said valve cylinders, a supply of fluid to be pumped, a port through which said supply communicates with said pumpd ing cylinder, a pumping piston in said pumping reversible means for reciprocating munication between said pumping cylinder and said valve cylinders, and reversible means for f reciprocating said pistons in said-cylinders, said ports being so positioned relative to the limits of the strokes of said pistons in their reciprocations that said ports openin succession, with a time interval between the opening ofeach of said ports and the closing of the preceding port, in the operation of said means in either direction.

4.- A pump having a pumping cylinder anda plurality of valve cylinders, valve cylinders vwith saidpumping cylinder and. serving alternatively as'inlet and outlet openings for said valve cylinders, an

pumping piston in said pumping cylinder, pistons in said valve cylinders cooperating with the said ports, control communication between -said pumping cylinder 'andsaidyalve cylinders, and said pistons in said cylinders, said ports -being so positioned relative to the limits of the strokes of said pistons in their reciprocations that the valve cylinders are at no time in communication with'each other and thatin at least one stage of a reciprocation cycle'both ports are closed for a substantial portion of the cycle. vDOUGLAS N. EVANS.

ports connecting said alternative outlet or l inlet opening for each of said valve cylinders, a 

